<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>图书详情</title>
</head>
<body>
{# book和heros是键 #}
<h1>{{ book.btitle }}</h1>
英雄信息如下:<br/>
<ul>
    {% for hero in heros %}
        <li>{{ hero.hname }}--{{ hero.hcomment }}</li>
    {% empty %}
        <li>没有英雄信息</li>
    {% endfor %}
</ul>
</body>
</html>